"Since ancient times natural resources have been used worldwide for medicinal purposes. Some Satureja species have revealed antibacterial activity against Gram-negative and Gram-positive bacteria. Little
is known about antimicrobial activity by flavonoids from S. boliviana, a native plant in Argentina that grows in the provinces of San Luis, Tucum?n, Salta and Jujuy. The present study examined the antimicrobial activity
of the total extract and four fractions (n-hexane, chloroform, ethyl acetate and water) from S. boliviana against four ATCC collection strains, E. faecalis 29212, S. aureus 29213, E. coli 25922 and Ps. aeruginosa 27853 and
two clinically isolated strains, Shigella sonnei and Salmonella enteritidis. The Minimum Inhibitory Concentration (MIC) of the extracts was analyzed with Mueller Hinton agar according to the NCCLS standards.
The water extract did not show any activity. The total extract had a MIC of 5,000 ?g/ml against all the microorganisms assayed except for Sh. sonnei, which was 10,000 ?g/ml. The chloroform and n-hexane fractions
did not show activity against the strains assayed with the exception of S. aureus with MICs of 5,000 ?g mL G1 and <2,000 ?g mLG , respectively. The ethyl acetate fraction demonstrated more activity against S. aureus (2,000
1 ?g mLG instead of 5,000 ?g mLG ) and Sh. sonnei (2,000 ?g mLG instead of 10,000 ?g mLG ) than the total 1 1 1 1 fraction.The inhibitory activity of the total fraction and ethyl acetate was compared with the MIC of clinically
used antibiotics standardized for ATCC strains. MICs of the total fraction and ethyl acetate between 2,000 and 5,000 ?g mLG against the ATCC strains were equivalent to the MICs of the antibiotics that varied between 0.121 and 64 ?g mLG . The inhibitory effect of the S. boliviana extracts against the microorganisms assayed would 1 justify the use of this popular plant, because phytomedicins tend to produce fewer collateral effects and acquire less often microbial resistance when compared to semi-synthetic antibiotics."